Do you mean when you click on a sidebar tab it links you to a page? Unfortunately this is not possible on the sidebar tab shortcode. You need to modify the sidebar tab function to make this kind of change work. You can hire a freelancer/developer for this job.

Or you just want to put a link inside the sidebar tab content? You can use html tag like this This is a link to page inside the sidebar tab content.

It looks like you are not actually using the sidebar tabs but instead the regular tabbed shortcode. So what you’ll need to do is try adding the following CSS to your Quick CSS (located under the Styling Tab in the theme options) or the custom.css file in the css folder of your theme files:

.js_active .tab {
font-size: 13px;
}

I’ve already changed the font size from 11px to 13px so adjust from there as needed.